When a short-term hazard condition is detected, the gas detection system must automatically close the shut-off valve at the source on gas supply piping and tubing related to the system being monitored for which gas is detected.

A continuous gas-detection system is required to detect the presence of gas at or below the permissible exposure limit or ceiling limit.

The detection system must:

Initiate a local alarm and transmit a signal to a constantly attended control station (exceptions may apply)

Be capable of monitoring the room or area in which the gas is stored at or below the permissible exposure limit or ceiling limit and the discharge from the treatment system at or below 1/2 IDLH (Immediately Dangerous to Life and Health) limit

The alarm must be both inside and outside the storage area. The audible alarm must be distinct from all other alarms.

An oxygen sensor may be required if it is determined that the location where this compressed gas is being used or stored presents a risk of asphyxiation. Advanced Micro Instruments Inc. makes a cost effective oxygen sensor.

Class III gases, flammable gases, and oxidizing gases are conditional, depending on the application and the specific gas in question, and will be determined by the EH&S Chemical Hygiene Officer, (858) 822-1579.

Be provided with self-closing limited access ports or non-combustible windows to give access to equipment controls

Average face velocity at the face of the access ports or windows shall not be less than 200 feet per minute (1.01 m/s) with a minimum of 150 feet per minute (0.76 m/s) at any 1 point of the access port or window

Connected to an approved exhaust system

Equipped with automatic fire sprinkler system protection, and must be constructed and ventilated according to code requirements.Be provided with self-closing doors

Be constructed of not less than 0.097 –inch (2.46 mm) (12 gage) steel

Cabinets containing more than 3 cylinders must be reviewed byEnvironment, Health and Safety to ensure safe storage.

Use a flow-limiting device to restrict hazardous gas flow rates to just over maximum flow required (e.g., flow restricting orifice). These devices must be installed immediately downstream of each gas cylinder.

For small scale experiments, such as fume hood use, a needle valve is sufficient.

For large cylinders, a flow restricting orifice must be installed by the gas supplier in the cylinder valve or installed in the gas purge panel.

Treatment systems must be designed to reduce the maximum allowable discharge concentration of the gas to 1/2 IDLH (Immediately Dangerous to Life and Health) at the point of discharge to the atmosphere.

When more than 1 gas is emitted to the treatment system, the treatment system must be designed to handle the worst-case release based on the release rate, the quantity, and the IDLH for all the gases stored or used.